This application is related to and claims priority from Japanese Patent Applications No. Hei. 11-158424 filed on Jun. 4, 1999, No. Hei. 11-196346 filed on Jul. 9, 1999, and No. 2000-71059 filed on Mar. 9, 2000, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a refrigerant evaporator for evaporating refrigerant of a refrigerant cycle, which is suitable for a vehicle air conditioner.
2. Related Art
In a conventional refrigerant evaporator, plural aluminum tubes having therein refrigerant passages are laminated, and plural corrugated fins made of aluminum are disposed between adjacent tubes to increase heat conductive area of air. For reducing the weight of the evaporator, a tube plate thickness is thinned until 0.4 mm. However, the relationship between the thinned tube plate thickness and the heat-conductive performance of the evaporator is not described sufficiently.
In view of the foregoing problems, it is an object of the present invention to provide a refrigerant evaporator having a sufficiently thinned tube plate thickness, in which conditions for obtaining the maximum heat-conductive performance are found so that the heat-conductive performance of the evaporator is improved.
It is an another object of the present invention to provide a refrigerant evaporator in which the heat-conductive performance is improved while pressure-resistance strength of tubes is improved.
According to a first aspect of the present invention, a refrigerant evaporator includes a plurality of tubes through which refrigerant flows, and a plurality of corrugated fins, made of an aluminum material, each of which is disposed between adjacent tubes to increase a heat-conductive area of air passing through between the tubes. The tubes are made of an aluminum material and are arranged in parallel with each other in a laminating direction perpendicular to a flow direction of air. In the evaporator, the tubes have a tube plate thickness TT being in a range of 0.10 mm-0.35 mm, each of the tubes has a tube height TH in the laminating direction, and the tube height TH is in a range of 1.5 mm-3.0 mm. Thus, by respectively setting the tube plate thickness TT and the tube height TH in the above-described ranges, pressure loss of refrigerant in a refrigerant passage of the tubes is made small, and heat-conductive area of air side becomes larger. As a result, heat-conductive performance of the evaporator is improved.
According to a second aspect of the present invention, in a refrigerant evaporator, each of the corrugated fins has a fin height FH in the laminating direction, and the fin height FH is in a range of 4.0 mm-7.5 mm. Therefore, in the evaporator, fin effect of the corrugated fins can be increased, and a decrease of heat-conductive percentage due to condensed water restricted. As a result, the heat-conductive percentage of the evaporator is improved.
In a refrigerant evaporator where each of the tubes is formed to have an outer wall portion formed into a flat cross section for defining therein an inner space and to have plural supports for partitioning the inner space of the outer wall portion into plural refrigerant passages, the outer wall portion has a plate thickness being in a range of 0.15 mm-0.35 mm, each of the tubes has a tube height TH being in a range of 1.5 mm-3.0 mm in the laminating direction, each of the supports has a plate thickness ST equal to or larger than 0.05 mm, and a distance L between adjacent supports is in a range of 0.8 mm-1.6 mm. By setting the distance L between adjacent supports at a value equal to or larger than 0.8 mm while the tube plate thickness TT and the tube height TH are respectively set in the above-described ranges, the pressure loss of refrigerant in the refrigerant passage of the tubes becomes smaller, heat-conductive area of air becomes larger, and heat-conductive performance is improved. Further, in the evaporator, by setting the plate thickness ST of the supports at a value equal to or larger than 0.05 mm and setting the distance L between adjacent supports at a value equal to or smaller than 1.6 mm, pressure-resistance strength of the tubes is improved, and heat-conductive percentage is improved.